The present invention relates to an antifriction device particularly useable in ski bindings.
Antifriction devices used in ski bindings particularly at the tip elements of such bindings are currently known.
Some of these devices are simply constituted by a plate which is directly coupled to the ski and is made of antifriction material, for example of the type commercially know by the trade-mark TEFLON: the sole of the boot rests on the plate once the binding has been closed.
Such know devices, however, have the disadvantage of not dynamically facilitating in any way the disengagement of the boot from the binding; for example the presence of mud on the surface of the boot heel can defect the characteristic of the material from which the plate is made.
As a partial solution to this disadvantage, plates have been provided which can slide along an axis which is essentially transverse to the ski, by means of adapted ball bearings which interact with the plates and which reduce, during release, the friction between the sole of the boot and the ski; the movement for the release of the boot from the binding is thus facilitated.
Even this solution, however, is not optimum, since during release there is no reduction in the friction between the sole of the boot and the plate.
As a partial solution to these disadvantages, devices are known wherein the plates are connected to the tip element so that a rotation of the tip element leads to a rotation of the plate as well, so as to facilitate the release of the boot from the binding.
The disadvantage of the solution consists of the fact that the movement of the plate activated directly by the movement of the tip element; thus, each movement of the tip element is univocally matched by a movement of the plate, regardless of the value of the friction occurring between the sole of the boot and the surface of said plate.
This is a considerable limitation, since even a slight movement of the tip element, due for example to the stresses imparted thereto by the ski while skiing, can induce a release of the boot which is neither necessary nor desired.
A slight rotation of the tip element in fact imposes a rotation to the plate and thus arranges the boot off-axis with respect to the ski, and consequently also with respect to the binding, thereby facilitating its release.